For example, anabolic steroids such as Testosterone have a tendency to promote water retention through their ability to be aromatized into Estrogen via the aromatase enzyme. While such an effect might not be a concern for a strength athlete or a powerlifter (such an effect might even be beneficial or desired in such sports), this is not a desired effect for athletes involved in sports that involve speed and swiftness, such as sprinting. Instead, a sprinter, for example, would more likely opt for an anabolic steroid such as Stanozolol ( Winstrol ) or Oxandrolone ( Anavar ), which are two anabolic steroids unable to convert into Estrogen and therefore the issue of water retention, and therefore the issue of added weight that would slow the athlete down is avoided. Many athletes may also elect to ‘stack’ anabolic steroids in a given cycle (stacking refers to the practice of combining more than one anabolic steroid in a cycle). In the case of cycle stacks, an individual might be able to increase the synergy and synergistic effects between the anabolic steroids to create a highly anabolic environment or to create a stack that might assist the user in favoring certain particular athletic or physique goals. These are some of the major reasons as to why the development of different types of steroids has been done.
Stanozolol is the generic name of stanozolol in English , German , French , and Japanese and its INN , USAN , USP , BAN , DCF , and JAN , while stanozololum is its name in Latin , stanozololo is its name in Italian and its DCIT , and estanozolol is its name in Spanish .    Androstanazole , stanazol , stanazolol , and estanazolol are unofficial synonyms of stanozolol.   The drug is also known generically by its former developmental code names NSC-43193 and WIN-14833 . 
Stephan Bonnar and Josh Barnett , mixed martial arts (MMA) fighters from the UFC and PRIDE Fighting Championships , have also tested positive for the banned substance.  After the World Extreme Cagefighting show on January 20, 2006 Muay Thai turned MMA fighter Kit Cope also tested positive for boldenone.  Following the Strikeforce card on June 22, 2007 former PRIDE and UFC fighter Phil Baroni tested positive for boldenone, as well as stanozolol .  At a K-1 WGP event in Las Vegas on August 17, 2007 two fighters, Rickard Nordstrand and Zabit Samedov , both tested positive for boldenone.  Alexandre Franca Nogueira tested positive for boldenone in July 2008.